Help With Barn Lighting

[baz222]

hello all, having a little trouble. i went to look at a job at a farm this week, and the farmer wants some lights in his barn. he doesnt want the whole thing lit up, just certain areas. there is a 3-phase feed to the barn with only a single phase CU with two 16A mcb's fitted. 1 x 16A radial socket circuit in at the moment..

i was thinking of some low energy sodium Flood lights, probably of only 70W each x 12off. and also mabey low energy 7 x 150W sodium lights. with 3-4 light switches.

thats a total output 1890W.


is there anything i should know about sodium lights?
should the lights be wired on seperate circuitts?
what cable should be used within a barn?
would contactors need to be fitted, if so how would one bet fit these?
barn is used for holding cows, though the cows are not bred for milk so the type of lighting is not too important. he wants low energy lighting if possible.
if you have any information i require could you please help.



thanks

 

[bernardgreen]

If the cows are fed in the barn then there may be requirements about preventing toxic materials from damaged lamps falling into the feed.

 

[Steve]

My replies in bold

hello all, having a little trouble. i went to look at a job at a farm this week, and the farmer wants some lights in his barn. he doesnt want the whole thing lit up, just certain areas. there is a 3-phase feed to the barn with only a single phase CU with two 16A mcb's fitted. 1 x 16A radial socket circuit in at the moment..
is there scope in the budget for changing this? not that you need to, one phase is sufficient for this job.

i was thinking of some low energy sodium Flood lights, probably of only 70W each x 12off. and also mabey low energy 7 x 150W sodium lights. with 3-4 light switches.
dont use switches, see below.

thats a total output 1890W.


is there anything i should know about sodium lights?

Yes, they give off poor light. Maybe consider half and half sodium and metal halide (I think they actually use the same control gear).

should the lights be wired on seperate circuitts?
I'd split them so that they arent going to be tripping MCBs on startup - they have quite a surge sometimes, C rated MCBs will be needed.

what cable should be used within a barn?
SWA or Pyro

would contactors need to be fitted, if so how would one best fit these?
if you fit contactors, the opportunity is there to fit timers and photocells etc (best bet for discharge lighting - they dont like frequent switching). If the farmer wants switched control, tell him his best bet is high intensity fluorescent

barn is used for holding cows, though the cows are not bred for milk so the type of lighting is not too important. he wants low energy lighting if possible.
low pressure sodium is the most efficient in terms of lumens per watt, but all those lumens are orange, so its not a good light. high pressure sodium (which I assume you are talking about) is slightly less efficient, but the colour rendition is much better. Metal halide and fluorescent are approximately equal in terms of colour and light output per watt AFAIK

 

[ban-all-sheds]

My replies in bold

Please don't start that.

 

[ban-all-sheds]

is there anything i should know about sodium lights?

Have a search here - I'm sure there was something recently about the frequency response of cows eyes, and the suitability of sodium lighting.

 

[baz222]

thanks for the detailed reply. the thing is the farmer only want the lights to be switched, as he is not often down there and only needs them while he is working in the barn.

so contactors aren't needed then for this installation if I fit high intensity fluorescents, but are needed if using SON etc...?
money is an issue on this job.

so are you saying you would wire 4 circuits of seperate rcd's?

could you give me an idea of the type of lights you preferred if possible?

thank you for the replies so far. i haven't undertaken work outside of houses before, so i am keen to learn a new skill.

 

[ban-all-sheds]

You should read Section 705.

 

[Steve]

contactors - depends how you want to switch the lights.

Regardless of anything else, you will need several circuits of SONs of you go this route. So if you need timer / photocell, you will need one or two 4-pole contactors to control all the circuits at once.

You need to ask the farmer how he intends to use these lights.

 

[baz222]

thanks - i have read BRB section 705.


contactors - each lighting circuit will require a separate contactor.
so basically i need 4 contactors for the 4 different switched circuits.?

the farmer is to use the two middle sets of lights (8 off) for general use when he is in the barn(once a night say). all the rest of the lights will only be used when needed. (less frequent).

 

[Steve]

No for 4 lighting circuits to be switched together you need one 4-pole contactor. You can get them in 1-, 2- and 4-pole varieties.

 

[baz222]

No, lighting circuits will require seperate switching

 

[baz222]

What does anyone think of these lights??

www.tlc-direct.co.uk/Products/GLSL226W.html


anybody used this type of low watt light??

 

[RF Lighting]

It's going to be naff all use to light a barn.

How big is this barn? It is your average say 20M by 10M barn as found on most small holdings?

 

[flameport]

Nothing wrong with those PL floodlights, but unless the barn is tiny, they won't be anywhere near bright enough.

These would be more likely choices:
http://www.tlc-direct.co.uk/Main_Index/Lighting_Menu_Index/Low_Bay/index.html

 

[RF Lighting]

I was just building to low bays. Talk about stealing my thunder

I'm going to mention 20AX switches before any one beats me to that